Among the compounds of formula (I), both the 3-methyl-2-hexenyl acetate and the 3-methyl-2-heptenyl formate possess a known structure. In particular, the preparation of 3-methyl-2-hexenyl acetate is described by Nasarow et al., in Zh. Obshch. Khim, 18, 1948, 656,661,663, whereas, the preparation of the 3-methyl-2-heptenyl formate is described by Y. Kuwahara in Agric. Biol. Chem. (1982), 46(7), 1855-60. On the other hand, none of the prior art documents mentions either the organoleptic properties of the compounds of formula (I), or any use of said compounds in the field of perfumery.
This is all the more surprising when knowing that some linear esters which possess a chemical structure relatively close to that of the compounds of formula (I) are well-known odorant compounds. One can cite in particular 2-hexenyl butanoate, 2-hexenyl phenyl acetate, 2-hexenyl propanoate or yet 2-hexenyl acetate. Though these compounds are listed in reference texts such as S. Arctander, Perfume and Flavor Chemicals, 1969, Montclair, N.J., USA, none of the substituted derivatives of formula (I) has been described as having odorant properties.